I get "The system cannot find the path specified. (Exception from HRESULT: 0x80070003)" when trying to save a file in Visual Studio

I can open a code file and see its contents fine in Visual Studio, but when I try to ctrl+s I get the following error:

The system cannot find the path specified. (Exception from HRESULT: 0x80070003)

This happens even if I delete the file and re-create it, or even clone my whole repo to elsewhere and then try and edit the file. How do I fix?

I managed to fix this by opening Visual Studio in administrator mode, editing said file, and then saving. It saved fine, and subsequently I've been able to edit and save without being in admin mode